A battery cell has been proposed as a clean, efficient and environmentally responsible power source for electric vehicles and various other applications. One type of battery cell is known as the lithium-ion battery. The lithium-ion battery is rechargeable and can be formed into a wide variety of shapes and sizes so as to efficiently fill available space in electric vehicles. For example, the battery cell may be in the form of a prismatic can.
A plurality of the battery cells can be provided in a battery cell pack or module to provide an amount of power sufficient to operate electric vehicles. Battery cells such as lithium-ion battery cells are known to generate heat during operation and as a result of a charge cycle when recharging. When overheated or otherwise exposed to high-temperature environments, undesirable effects can impact the operation of lithium-ion batteries. In typical battery cell modules, the battery cells expand and contract with change in temperature.
Cooling systems are typically employed with battery cell modules to militate against the undesirable overheating conditions. Conventional cooling systems have included repeating elements such as cooling plates disposed between individual battery cells within the battery cell module. The repeating elements define air cooling gaps or channels in between the battery cells for cooling the battery cell module in operation by circulation of air through the battery cell module. However, in known battery cell modules where alternating battery cells and repeating elements are rigidly fixed under compression, the expansion of the battery cells with the change in temperature can undesirably result in an overcompression of the battery cells, as well as a reduction in width of the cooling gaps, that negatively impacts a useable life of the battery cell module.
There is a continuing need for a battery cell module that allows for the repeating elements to move and accommodate an entire range of thicknesses of the battery cells during expansion of the battery cells in operation, while also retaining the repeating elements in other directions and militating against overcompression of the battery cells. Desirably, the battery cell module decouples the expansion of the battery cells from widths of the cooling gaps defined by the repeating elements and the battery cells, maintains a substantially constant width for each of the cooling gaps between the repeating elements and the battery cells, and allows both thicknesses of the battery cells and the widths of the cooling gaps to be optimized.